1. Field of the Invention
The present invention relates to novel compounds that function as proteolytic enzyme inhibitors, and particularly to a new class of inhibitors of thrombin production via factor Xa inhibition, their pharmaceutically acceptable salts, and pharmaceutically acceptable compositions thereof.
2. Related Art
Proteases are enzymes that cleave proteins at single, specific peptide bonds. Proteases can be classified into four generic classes: serine, thiol or cysteinyl, acid or aspartyl, and metalloproteases (Cuypers et al., J. Biol. Chem. 257:7086 (1982)). Proteases are essential to a variety of biological activities, such as digestion, formation and dissolution of blood clots, reproduction and the immune reaction to foreign cells and organisms. Aberrant proteolysis is associated with a number of disease states in man and other mammals. The human neutrophil proteases, elastase and cathepsin G, have been implicated as contributing to disease states marked by tissue destruction. These disease states include emphysema, rheumatoid arthritis, comeal ulcers and glomerular nephrtis. (Barret, in Enzyme Inhibitors as Drugs, Sandler, ed., University Park Press, Baltimore, (1980)). Additional proteases such as plasmin, C-1 esterase, C-3 convertase, urokinase, plasminogen activator, acrosin, and kallikreins play key roles in normal biological functions of mammals. In many instances, it is beneficial to disrupt the function of one or more proteolytic enzymes in the course of therapeutically treating a mammal.
Serine proteases include such enzymes as elastase (human leukocyte), cathepsin G, plasmin, C-1 esterase, C-3 convertase, urokinase, plasminogen activator, acrosin, chymotrypsin, trypsin, thrombin, factor Xa and kallikreins.
Human leukocyte elastase is released by polymorphonuclear leukocytes at sites of inflammation and thus is a contributing cause for a number of disease states. Cathepsin G is another human neutrophil serine protease. Compounds with the ability to inhibit the activity of these enzymes are expected to have an anti-inflammatory effect useful in the treatment of gout, rheumatoid arthritis and other inflammatory diseases, and in the treatment of emphysema. Chymotrypsin and trypsin are digestive enzymes. Inhibitors of these enzymes are useful in treating pancreatitis. Inhibitors of urolkinase and plasminogen activator are useful in treating excessive cell growth disease states, such as benign prostatic hypertrophy, prostatic carcinoma and psoriasis.
The serine protease thrombin occupies a central role in hemostasis and thrombosis, and as a multifactorial protein, induces a number of effects on platelets, endothelial cells, smooth muscle cells, leukocytes, the heart, and neurons. Activation of the coagulation cascade through either the intrinsic pathway (contact activation) or the extrinsic pathway (activation by exposure of plasma to a non-endothelial surface, damage to vessel walls or tissue factor release) leads to a series of biochemical events that converge on thrombin. Thrombin cleaves fibrinogen ultimately leading to a hemostatic plug (clot formation), potently activates platelets through a unique proteolytic cleavage of the cell surface thrombin receptor (Coughlin, Seminars in Hematology 31(4):270-277 (1994)), and autoamplifies its own production through a feedback mechanism. Thus, inhibitors of thrombin function have therapeutic potential in a host of cardiovascular and non-cardiovascular diseases.
Factor Xa is another serine protease in the coagulation pathway. Factor Xa associates with factor Va and calcium on a phospholipid membrane thereby forming a prothrombinase complex. This prothrombinase complex then converts prothrombin to thrombin (Claeson, Blood Coagulation and Fibrinolysis 5:411-436 (1994); Harker, Blood Coagulation and Fibrinolysis 5 (Suppl 1):S47-S58 (1994)). Inhibitors of factor Xa are thought to offer an advantage over agents that directly inhibit thrombin since direct thrombin inhibitors still permit significant new thrombin generation (Lefkovits and Topol, Circulation 90(3):1522-1536 (1994); Harker, Blood Coagulation and Fibrinolysis 5 (Suppl 1):S47-S58 (1994)).
Direct thrombin inhibitors of various structural classes have been identified recently (Tapparelli et al., Trends in Pharmacological Sciences 14:366-376 (1993); Claeson, Blood Coagulation and Fibrinolysis 5:411-436 (1994); Lefkovits and Topol, Circulation 90(3):1522-1536 (1994)). Representative compounds that act by inhibiting the active site of thrombin include the xcex1-chloroketone D-phenylalanyl-L-prolyl-L-arginyl chloromethylketone (PPACK), the boroarginine DUP714, the peptide arginal GYK114766, the cyclic peptides cyclotheonamides A and B, the benzamidine NAPAP, and the arylsulphonylarginine argatroban. The thrombin inhibitory peptides hirudin and hirulogs additionally span through the active and exosite domains of thrombin. The peptide hirugen and single-stranded DNA aptamers inhibit thrombin through exosite occupancy. These classes of antithrombotic agents still suffer from one or more of the following liabilities: (1) poor oral bioavailability due to the peptidic or oligonucleotidic nature of these agents, or high molecular weight or charged nature of the agents; (2) excessive bleeding complications; (3) poor selectivity towards thrombin versus other serine proteases (that may lead to severe and sometimes fatal hypotension and respiratory depression in animal models); (4) liver toxicity; or (5) cost effectiveness.
An alternative approach for inhibiting thrombin function is to inhibit factor Xa. Factor Xa associates with factor Va and calcium on a phospholipid membrane thereby forming a prothrombinase complex. This prothrombinase complex then converts prothrombin to thrombin (Claeson, Blood Coagulation and Fibrinolysis 5:411-436 (1994); Harker, Blood Coagulation and Fibrinolysis 5 (Suppl 1):S47-S58 (1994)). Inhibitors of factor Xa are thought to offer an advantage over agents that directly inhibit thrombin since direct thrombin inhibitors still permit significant new thrombin generation (Lefkovits and Topol, Circulation 90(3):1522-1536 (1994); Harker, Blood Coagulation and Fibrinolysis 5 (Suppl 1):S47-S58 (1994)). Indeed, continuous generation of new thrombin rather than reexposure of preformed clot-bound thrombin is thought to be responsible in part for the phenomenon of reocclusion since markers of thrombin generation have been found to increase during and after thrombolytic treatment for myocardial infarction. Thus, it is now believed that increased thrombin activity associated with thrombolysis is due at least in part to new thrombin generation.
Specific protein factor Xa inhibitors, such as the leech-derived, 119-amino acid protein antistasin and the soft tick-derived protein TAP (tick anticoagulant peptide) accelerated clot lysis and prevented reocclusion when given as adjuncts to thrombolysis (Mellott et al., Circulation Research 70:1152-1160 (1992); Sitko et al., Circulation 85:805-815 (1992)). U.S. Pat. No. 5,385,885, issued Jan. 31, 1995, discloses smooth muscle cell proliferation inhibitory activity of both TAP and antistasin. Additionally, TAP and antistasin have been shown to reduce experimental restenosis. These results suggest that factor Xa may play a role in the restenosis process through its effects upon thrombus formation or through its mitogenic potential (Ragosta et al., Circulation 89:1262-1271 (1994)). The peptide ecotin is another selective, reversible, tight-binding inhibitor of factor Xa that exhibits potent anticoagulant activity (Seymour et al., Biochemistry 33:3949-3959 (1994); PCT Published Application WO 94/20535, published Sep. 14, 1994). ixodidae, argasin, and ancylostomatin are other representative peptidic factor Xa inhibitors isolated from animals that feed on blood (Markwardt, Thrombosis and Hemostasis 72:477-479 (1994)).
Non-peptide diamidino derivatives, such as (+)-(2S)-2-[4-[[(3S)-1-acetimidoyl-3-pyrrolidinyl]oxy]phenyl]-3-[7-amidino-2-naphthyl]propanoic acid hydrochloride pentahydrate (DX-9065a), exhibit anticoagulant activity (Tidwell et al., Thrombosis Research 19:339-349 (1980); Yamazaki et al., Thrombosis and Hemostasis 72:393-395 (1994); Hara et al., Thrombosis and Hemostasis 71:314-319 (1994); Nagahara et al., Journal of Medicinal Chemistry 37:1200-1207 (1994)). Synthetic amidino derivatives of phenylalanine and cycloheptanone have also shown potent factor Xa inhibition (Sturzebecher et al., Thrombosis Research 54:245-252 (1989)).
A need continues to exist for non-peptidic compounds that are potent and selective protease inhibitors, and which possess greater bioavailability and fewer side-effects than currently available protease inhibitors. Accordingly, new classes of potent protease inhibitors, characterized by potent inhibitory capacity and low mammalian toxicity, are potentially valuable therapeutic agents for a variety of conditions, including treatment of a number of mammalian proteolytic disease states.
The present invention is directed to novel compounds having Formula I (below).
Also provided are processes for preparing compounds of Formula I.
The novel compounds of the present invention are potent inhibitors of proteases, especially trypsin-like serine proteases, such as chymotrypsin, trypsin, thrombin, plasmin and factor Xa. Certain of the compounds exhibit indirect antithrombotic activity via selective inhibition of factor Xa, or are intermediates useful for forming compounds having antithrombotic activity. Also provided are methods of inhibiting or treating aberrant proteolysis in a mammal and methods of treating thrombosis, ischemia, stroke, restenosis or inflammation in a mammal by administering an effective amount of a compound of Formula I.
The invention includes a composition for treating thrombosis, ischemia, stroke, restenosis or inflammation comprising a compound of the invention in a pharmaceutically acceptable carrier. These compositions may optionally include anticoagulants, antiplatelet agents, and thrombolytic agents. The compositions can be added to blood, blood products, or mammalian organs in order to effect the desired inhibitions.
A first aspect of the invention is novel compounds of Formula I: 
or pharmaceutically acceptable salts thereof; wherein
Q is C6-14 aryl, C6-14 ar(C1-4)alkyl, C6-14 ar(C2-4)alkenyl, pyridyl, thienyl, indolyl, quinolinyl, benzothienyl, or imidazolyl; any of which can include one or more optional substituents independently selected from halo, trifluoromethyl, hydroxy, amino, nitro, cyano, C1-3 alkoxy, C1-3 alkyl, methylenedioxy, carboxyamino, C1-4 alkoxycarbonylamino, C6-10 aryloxycarbonylamino, C7-11aralkoxycarbonylamino, aminocarbonyl, mono- or di-(C1-4)alkylaminocarbonyl, acetamido, amidino, pyridyl, naphthyl, pyrimidinyl, alkenyl, mono- or di- (C1-4)alkylamino, or combinations thereof;
X is methylene, carbonyl, or sulfonyl;
R1 is hydrogen or C1-3 alkyl;
n is 1, 2 or 3;
m is 1-4, preferably 1 or 2;
R2 is hydrogen or C1-3 alkyl;
R3 is hydrogen or C1-3 alkyl; and
R4, R5 and R6 are independently hydrogen, hydroxy, C1-6 alkyl, C1-6 alkoxy, cyano or xe2x80x94CO2Rw, where Rw, in each instance, is preferably one of C1-4alkyl, C4-7cycloalkyl, benzyl, or Rw is one of 
where Rd, Re and Rg are each hydrogen, Rf is methyl, and Rh is benzyl or tert-butyl.
Preferred values of Q include aryl such as phenyl, biphenyl, or naphthyl; or aralkyl such as benzyl, phenethyl or naphthylmethyl; or thienyl. Any of these groups can be optionally substituted as defined above.
Suitable values include naphth-1-yl, naphth-2-yl, 5-dimethylaminonaphthlyl, 6-chloronaphth2yl, 6-bromonaphth-2-yl, benzyl, 2-nitrobenzyl, phenyl, 2-methylphenyl, 3-methylphenyl, 4-(n-propyl)phenyl, 4-(t-butyl)phenyl, 4-(t-amyl)phenyl, 4-methoxyphenyl, 4-iodophenyl, 4-fluorophenyl, 4-chlorophenyl, 3,4-dichlorophenyl, 4-nitrophenyl, 4-methylphenyl, 4-ethylphenyl, 4-ethenylphenyl, 3,4-dimethoxyphenyl, and 2-phenylethenyl.
Additional suitable values include 4-(2-methylphenyl)phenyl, 4-(2-methoxyphenyl)phenyl, 4-(3-chlorophenyl)phenyl, 4-(3-fluorophenyl)phenyl, 4-(3-methoxyphenyl)phenyl, 4-(4-fluorophenyl)phenyl, 4-(4-methylphenyl)phenyl, 4-(4-methoxyphenyl)phenyl, 4-(2,4-difluorophenyl)phenyl, 4-(3,4-dichlorophenyl)phenyl, 4-(3,4-dimethoxyphenyl)phenyl, 4-naphth-2-ylphenyl, 4-pyrid-4-ylphenyl, 4-pyrid-2-ylphenyl, biphenyl {(4-phenyl)phenyl}, 4-(4-chloro phenyl)phenyl, 4-pyrimidin-5-ylphenyl, and 5-(pyrid-5-yl)thien-2-yl.
Preferred values of n are 1 and 2.
Preferred values of X are SO2 or C(O), most preferably SO2.
Preferred values of m include 1 or 2, most preferably 1.
Suitable values for R1, R2, and R3 include hydrogen, methyl, ethyl, n-propyl and isopropyl. Most preferably, each of R1, R2, and R3 is hydrogen.
Suitable values of R4, R5 and R6 include hydrogen, methyl, ethyl, propyl, n-butyl, hydroxy, methoxy, ethoxy, cyano, xe2x80x94CO2CH3, xe2x80x94CO2CH2CH3 and xe2x80x94CO2CH2CH2CH3. In the most preferred embodiments, R4, R5 and R6 are each hydrogen.
A preferred sub-genus of compounds of the present invention are those of Formula I wherein:
Q is phenyl, biphenylyl, naphthyl benzyl, phenethyl, naphthylmethyl, or thienyl, more preferably phenyl or biphenyl, any of these groups being optionally substituted by one to three optional substituents independently selected from halo, trifluoromethyl, hydroxy, amino, nitro, cyano, C1-3 alkoxy, C1-3 alkyl, methylenedioxy, carboxyamino, C1-4 alkoxycarbonylamino, C6-10 aryloxycarbonylamino, C7-11aralkoxycarbonylamino, aminocarbonyl, mono- or di-(C1-4)alkylaminocarbonyl, acetamido, amidino, pyridyl, naphthyl, pyrimidinyl, alkenyl, mono- or di- (C1-4)alkylamino;
X is carbonyl, or sulfonyl, more preferably sulfonyl;
n is 1 or 2;
m is 1 or 2, more preferably 1;
R1, R2 and R3 are hydrogen; and
R4, R5 and R6 are independently hydrogen, hydroxy, C1-6alkyl C1-6, alkoxy, cyano or xe2x80x94CO2Rw, where Rw, in each instance, is preferably one of C1-4alkyl, C4-7cycloalkyl, benzyl, or Rw is one of 
where Rd, Re and Rg are each hydrogen, Rf is methyl, and Rh is benzyl or tert-butyl.
Compounds within the scope of the invention are described in the Examples.
It is also to be understood that the present invention is considered to include stereoisomers as well as optical isomers, e.g. mixtures of enantiomers as well as individual enantiomers and diastereomers, which arise as a consequence of structural asymmetry in selected compounds of the present series.
The compounds of Formula I may also be solvated, especially hydrated. Hydration may occur during manufacturing of the compounds or compositions comprising the compounds, or the hydration may occur over time due to the hygroscopic nature of the compounds.
Certain compounds within the scope of Formula I are derivatives referred to as prodrugs. The expression xe2x80x9cprodrugxe2x80x9d denotes a derivative of a known direct acting drug, which derivative has enhanced delivery characteristics and therapeutic value as compared to the drug, and is transformed into the active drug by an enzymatic or chemical process. Useful prodrugs are those where R4, R5 and/or R6 are xe2x80x94CO2Rw, where Rw is defined above.
When any variable occurs more than one time in any constituent or in Formula I, its definition on each occurrence is independent of its definition at every other occurrence. Also, combinations of substituents and/or variables are permissible only if such combinations result in stable compounds.
The term xe2x80x9calkylxe2x80x9d as employed herein by itself or as part of another group refers to both straight and branched chain radicals of up to 10 carbons, unless the chain length is limited thereto, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethylpentyl, nonyl, or decyl.
The term xe2x80x9calkenylxe2x80x9d is used herein to mean a straight or branched chain radical of 2-10 carbon atoms, unless the chain length is limited thereto, including, but not limited to, ethenyl, 1-propenyl, 2-propenyl, 2-methyl-1-propenyl, 1-butenyl, 2-butenyl, and the like. Preferably, the alkenyl chain is 2 to 8 carbon atoms in length most preferably from 2 to 4 carbon atoms in length.
The term xe2x80x9calkynylxe2x80x9d is used herein to mean a straight or branched chain radical of 2-10 carbon atoms, unless the chain length is limited thereto, wherein there is at least one triple bond between two of the carbon atoms in the chain, including, but not limited to, acetylene, 1-propylene, 2-propylene, and the like. Preferably, the alkynyl chain is 2 to 8 carbon atoms in length, most preferably from 2 to 4 carbon atoms in length.
In all instances herein where there is an alkenyl or alkynyl moiety as a substituent group, the unsaturated linkage, i.e., the vinylene or acetylene linkage is preferably not directly attached to a nitrogen, oxygen or sulfur moiety.
The terms xe2x80x9calkoxyxe2x80x9d refers to any of the above alkyl groups linked to an oxygen atom.
The term xe2x80x9carylxe2x80x9d as employed herein by itself or as part of another group refers to monocyclic or bicyclic aromatic groups containing from 6 to 12 carbons in the ring portion, preferably 6-10 carbons in the ring portion, such as phenyl, biphenyl, naphthyl or tetrahydronaphthyl.
The term xe2x80x9caralkylxe2x80x9d or xe2x80x9carylalkylxe2x80x9d as employed herein by itself or as part of another group refers to C1-6alkyl groups as discussed above having an aryl substituent, such as benzyl, phenylethyl or 2-naphthylmethyl.
The term xe2x80x9cheteroarylxe2x80x9d as employed herein refers to groups having 5 to 14 ring atoms; 6, 10 or 14xcfx80 electrons shared in a cyclic array; and containing carbon atoms and 1, 2 or 3 oxygen, nitrogen or sulfur heteroatoms (where examples of heteroaryl groups are: thienyl, benzo[b]thienyl, naphtho[2,3-b]thienyl, thianthrenyl, furyl, pyranyl, isobenzofuranyl, benzoxazolyl, chromenyl, xanthenyl, phenoxathiinyl, 2H-pyrrolyl, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolizinyl, isoindolyl, 3H-indolyl, indolyl, indazolyl, purinyl, 4H-quinolizinyl, isoquinolyl, quinolyl, phthalazinyl, naphthyridinyl, quinazolinyl, cinnolinyl, pteridinyl, 4xcex1H-carbazolyl, carbazolyl, xcex2-carbolinyl, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl, isoxazolyl, furazanyl and phenoxazinyl groups).
The term xe2x80x9ccycloalkylxe2x80x9d as employed herein by itself or as part of another group refers to cycloalkyl groups containing 3 to 9 carbon atoms. Typical examples are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and cyclononyl.
The term xe2x80x9chalogenxe2x80x9d or xe2x80x9chaloxe2x80x9d as employed herein by itself or as part of another group refers to chlorine, bromine, fluorine or iodine with chlorine being preferred.
The term xe2x80x9cmonoalkylaminexe2x80x9d as employed herein by itself or as part of another group refers to an amino group which is substituted with one alkyl group having from 1 to 6 carbon atoms.
The term xe2x80x9cdialkylaminexe2x80x9d as employed herein by itself or as part of another group refers to an amino group which is substituted with two alkyl groups, each having from 1 to 6 carbon atoms.
The term xe2x80x9chydroxyalkylxe2x80x9d as employed herein refers to any of the above alkyl groups substituted by one or more hydroxyl moieties.
The term xe2x80x9ccarboxyalkylxe2x80x9d as employed herein refers to any of the above alkyl groups substituted by one or more carboxylic acid moieties.
The term xe2x80x9cheteroatomxe2x80x9d is used herein to mean an oxygen atom (xe2x80x9cOxe2x80x9d), a sulfur atom (xe2x80x9cSxe2x80x9d) or a nitrogen atom (xe2x80x9cNxe2x80x9d). It will be recognized that when the heteroatom is nitrogen, it may form an NRaRb moiety, wherein Ra and Rb are, independently from one another, hydrogen or C1 to C8 alkyl, or together with the nitrogen to which they are bound, form a saturated or unsaturated 5-, 6-, or 7-membered ring.
The abbreviation xe2x80x9ct-Amxe2x80x9d used herein refers to an active amyl moiety having the structure CH3CH2(CH3)2Cxe2x80x94.
The pharmaceutically-acceptable salts of the compounds of Formula I (in the form of water- or oil-soluble or dispersible products) include the conventional non-toxic salts or the quaternary ammonium salts which are formed, e.g., from inorganic or organic acids or bases. Examples of such acid addition salts include acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, camphorsulfonate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptanoate, glycerophosphate, hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydrojodide, 2-hydroxyethanesulfonate, lactate, maleate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oxalate, pamoate, pectinate, persulfate, 3-phenylpropionate, picrate, pivalate, propionate, succinate, sulfate, tartrate, thiocyanate, tosylate, and undecanoate. Base salts include ammonium salts, alkali metal salts such as sodium and potassium salts, alkaline earth metal salts such as calcium and magnesium salts, salts with organic bases such as dicyclohexylamine salts, N-methyl-D-glucamine, and salts with amino acids such as arginine, lysine, and so forth. Also, the basic nitrogen-containing groups may be quaternized with such agents as lower alkyl halides, such as methyl, ethyl, propyl, and butyl chloride, bromides and iodides; dialkyl sulfates like dimethyl, diethyl, dibutyl; and diamyl sulfates, long chain halides such as decyl, lauryl, myristyl and stearyl chlorides, bromides and iodides, aralkyl halides like benzyl and phenethyl bromides and others. Preferred acids for forming acid addition salts include HCl, acetic acid, trifluoroacetic acid and fumaic acid.
A second aspect of the present invention is directed to a method of treating thrombosis, ischemia, stroke, restenosis or inflammation comprising administering to a mammal in need of said treatment a therapeutically or prophylactically effective amount of a compound of Formula I.
The compounds of the present invention represent a novel class of potent inhibitors of metallo, acid, thiol and serine proteases. Examples of the serine proteases inhibited by compounds within the scope of the invention include leukocyte neutrophil elastase, a proteolytic enzyme implicated in the pathogenesis of emphysema; chymotrypsin and trypsin, digestive enzymes; pancreatic elastase, and cathepsin G, a chymotrypsin-like protease also associated with leukocytes; thrombin and factor Xa, proteolytic enzymes in the blood coagulation pathway. Inhibition of thermolysin, a metalloprotease, and pepsin, an acid protease, are also contemplated uses of compounds of the present invention. The compounds of the present invention are preferably employed to inhibit trypsin-like proteases.
The compounds of the present invention are distinguished by their ability to preferentially inhibit factor Xa in comparison to thrombin and/or plasmin. As factor Xa inhibitors, the compounds of the present invention inhibit thrombin production. Therefore, the compounds are useful for the treatment or prophylaxis of states characterized by abnormal venous or arterial thrombosis involving either thrombin production or action. These states include, but are not limited to: deep vein thrombosis; disseminated intravascular coagulopathy that occurs during septic shock, viral infections, and cancer; myocardial infarction; stroke; coronary artery bypass; hip replacement; and thrombus formation resulting from either thrombolytic therapy or percutaneous transluminal coronary angioplasty (PCTA). The compounds of the present invention may also be used as an anticoagulant in extracorporeal blood circuits. By virtue of the effects of both factor Xa and thrombin on a host of cell types, such as smooth muscle cells, endothelial cells and neutrophils, the compounds of the present invention find additional use in the treatment or prophylaxis of adult respiratory distress syndrome; inflammatory responses, such as edema; reperfusion damage; atherosclerosis; and restenosis following an injury such as balloon angioplasty, atherectomy, and arterial stent placement.
The compounds of the present invention may be useful in treating neoplasia and metastasis, as well as neurodegenerative diseases, such as Alzheimer""s disease and Parkinson""s disease.
The compounds of the present invention may be used in combination with thrombolytic agents, such as tissue plasminogen activator, streptokinase, and urokinase. Additionally, the compounds of the present invention may be used in combination with other antithrombotic or anticoagulant drugs such as, but not limited to, fibrinogen antagonists and thromboxane receptor antagonists.
Compounds of the present invention that are distinguished by their ability to inhibit thrombin may be employed for a number of therapeutic purposes. As thrombin inhibitors, compounds of the present invention inhibit thrombin production. Therefore, these compounds are useful for the treatment or prophylaxis of states characterized by abnormal venous or arterial thrombosis involving either thrombin production or action. These states include, but are not limited to, deep vein thrombosis; disseminated intravascular coagulopathy which occurs during septic shock, viral infections and cancer; myocardial infarction; stroke; coronary artery bypass; fibrin formation in the eye; hip replacement; and thrombus formation resulting from either thrombolytic therapy or percutaneous transluminal coronary angioplasty (PCTA). Other uses include the use of said thrombin inhibitors as anticoagulants either embedded in or physically linked to materials used in the manufacture of devices used in blood collection, blood circulation, and blood storage, such as catheters, blood dialysis machines, blood collection syringes and tubes, and blood lines. The compounds of the present invention may also be used as an anticoagulant in extracorporeal blood circuits.
By virtue of the effects of thrombin on a host of cell types, such as smooth muscle cells, endothelial cells and neutrophils, the compounds of the present invention find additional use in the treatment or prophylaxis of adult respiratory distress syndrome; inflammatory responses; wound healing; reperfusion damage; atherosclerosis; and restenosis following an injury such as balloon angioplasty, atherectomy, and arterial stent placement.
The compounds of the present invention may be useful in treating neoplasia and metastasis as well as neurodegenerative diseases, such as Alzheimer""s disease and Parkinson""s disease.
When employed as factor Xa inhibitors, the compounds of the present invention may be administered in an effective amount within the dosage range of about 0.1 to about 500 mg/kg, preferably between 0.1 to 10 mg/kg body weight, on a regimen in single or 2-4 divided daily doses.
The pharmaceutical compositions of the invention can be administered to any animal that can experience the beneficial effects of the compounds of the invention. Foremost among such animals are humans, although the invention is not intended to be so limited.
The pharmaceutical compositions of the present invention can be administered by any means that achieve their intended purpose. For example, administration can be by parenteral, subcutaneous, intravenous, intramuscular, intraperitoneal, transdermal, buccal, or ocular routes. Alternatively, or concurrently, administration can be by the oral route. The dosage administered will be dependent upon the age, health, and weight of the recipient, kind of concurrent treatment, if any, frequency of treatment, and the nature of the effect desired.
In addition to the pharmacologically active compounds, the new pharmaceutical preparations can contain suitable pharmaceutically acceptable carriers comprising excipients and auxiliaries that facilitate processing of the active compounds into preparations that can be used pharmaceutically.
The pharmaceutical preparations of the present invention are manufactured in a manner that is, itself, known, for example, by means of conventional mixing, granulating, dragee-making, dissolving, or lyophilizing processes. Thus, pharmaceutical preparations for oral use can be obtained by combining the active compounds with solid excipients, optionally grinding the resulting mixture and processing the mixture of granules, after adding suitable auxiliaries, if desired or necessary, to obtain tablets or dragee cores.
Suitable excipients are, in particular, fillers such as saccharides, for example, lactose or sucrose, mannitol or sorbitol, cellulose preparations and/or calcium phosphates, for example, tricalcium phosphate or calcium hydrogen phosphate, as well as binders, such as, starch paste, using, for example, maize starch, wheat starch, rice starch, potato starch, gelatin, tragacanth, methyl cellulose, hydroxypropylmethylcellulose, sodium carboxymethylcellulose, and/or polyvinyl pyrrolidone. If desired, disintegrating agents can be added, such as, the above-mentioned starches and also carboxymethyl-starch, cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof, such as, sodium alginate. Auxiliaries are, above all, flow-regulating agents and lubricants, for example, silica, talc, stearic acid or salts thereof, such as, magnesium stearate or calcium stearate, and/or polyethylene glycol. Dragee cores are provided with suitable coatings that, if desired, are resistant to gastric juices. For this purpose, concentrated saccharide solutions can be used, which may optionally contain gum arabic, talc, polyvinyl pyrrolidone, polyethylene glycol, and/or titanium dioxide, lacquer solutions and suitable organic solvents or solvent mixtures. In order to produce coatings resistant to gastric juices, solutions of suitable cellulose preparations, such as, acetylcellulose phthalate or hydroxypropylmethyl-cellulose phthalate, are used. Dye stuffs or pigments can be added to the tablets or dragee coatings, for example, for identification or in order to characterize combinations of active compound doses.
Other pharmaceutical preparations which can be used orally include push-fit capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a plasticizer, such as, glycerol or sorbitol. The push-fit capsules can contain the active compounds in the form of granules that may be mixed with fillers such as lactose, binders such as starches, and/or lubricants such as talc or magnesium stearate and, optionally, stabilizers. In soft capsules, the active compounds are preferably dissolved or suspended in suitable liquids, such as, fatty oils or liquid paraffin. In addition, stabilizers may be added.
Suitable formulations for parenteral administration include aqueous solutions of the active compounds in water-soluble form, for example, water-soluble salts, alkaline solutions and cyclodextrin inclusion complexes. Especially preferred alkaline salts are ammonium salts prepared, for example, with Tris, choline hydroxide, Bis-Tris propane, N-methylglucamine, or arginine. One or more modified or unmodified cyclodextrins can be employed to stabilize and increase the water solubility of compounds of the present invention. Useful cyclodextrins for this purpose are disclosed in U.S. Pat. Nos. 4,727,064, 4,764,604, and 5,024,998.
In addition, suspensions of the active compounds as appropriate oily injection suspensions can be administered. Suitable lipophilic solvents or vehicles include fatty oils, for example, sesame oil, or synthetic fatty acid esters, for example, ethyl oleate or triglycerides or polyethylene glycol-400 (the compounds are soluble in PEG400). Aqueous injection suspensions can contain substances that increase the viscosity of the suspension, for example, sodium carboxymethyl cellulose, sorbitol, and/or dextran. Optionally, the suspension may also contain stabilizers.
The present invention is also directed to methods of making compounds of Formula I, comprising:
coupling or condensing a compound of Formula II: 
or a salt thereof, where R4, R5 and R6 are as defined herein or optionally protected, and m is as defined herein, with a compound of Formula III: 
where R51 is H or Qxe2x80x94Xxe2x80x94, where Q, X, R1, R2, R3, R4, R5, and R6 are as defined herein. In general, R4, R5, and R6 groups may either be hydrogen or an amino protecting group.
Compounds of the present invention can be synthesized according to the following schemes.
Reagents and starting materials used in the following methods are commercially available from chemical vendors, including Aldrich, Advanced ChemTech, Bachem, Sigma, Fluka, and the like. During the synthesis of these compounds, functional groups are protected by blocking groups to prevent cross reaction. Examples of suitable blocking groups and their use are described in Greene, T. W. and Wuts, P. G. M., Protective Groups in Organic Synthesis, second edition, John Wiley and Sons, New York, N.Y. (1991). Blocking groups are also referred to herein as protective groups.
Scheme 1 details the synthetic steps to produce aminoalkoxyguanidine starting materials of Formula II. The variable xe2x80x9cmxe2x80x9d in the schemes has a value of from 1 to 8, preferably 1 or 2. The synthetic steps in this scheme are described in further detail and exemplified in Examples 1 and 2 of commonly assigned published PCT application WO 99/26926, published Jun. 3, 1999. 
Preparation of the xcex3- and xcex4-lactam starting materials III having a carboxymethyl group at the 1-position and an amino group possessing a suitable protective group Pb at the 3-position have been described previously by Freidinger et al., J. Org. Chem. 47:104-109 (1982). The analogous 7-membered ring lactam has also been described (Semple, J. E. et al., J. Med. Chem. 39:4531-4536 (1996). Alternatively, the xcex4-lactam can be synthesized by cyclization of ornithine with a suitable protective group on the xcex1-amino group using an amide coupling reagent such as 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride. The carboxymethyl group can then be installed by alkylation with an xcex1-bromoacetic acid ester using a base such as lithium bis(trimethylsilyl)amide in a solvent such as tetrahydrofuran or N,N-dimethylformamide, followed by saponification with aqueous methanolic hydroxide. The analogous xcex3-lactam can also be synthesized by a modified Curtius-type rearrangement at the xcex3-carboxyl group of glutamic acid having suitable protective groups on the xcex1-amino and xcex1-carboxy groups similar to that described by Scholtz and Bartlett, Synthesis:542-544 (1989). Spontaneous cyclization is then effected by removal of the resulting xcex3-amino protective group and conversion to the free base (if necessary). Introduction of the carboxymethyl side chain can then be carried out as previously described. 
Scheme 2 illustrates the coupling of the synthesis of compounds of the invention starting with the coupling of starting materials of Formulae II and III. The starting materials can be coupled using standard coupling agents such as N,Nxe2x80x2-dicyclohexylcarbodiimide and other well-known agents described in The Peptides: Analysis, Synthesis, Biology, Gras, E. et al., eds., Academic Press, New York, N.Y. (1979-1987), Volumes 1 to 8. The protective group Pb can then be removed using conditions described in Greene, T. W. and Wuts, P. G. M., Protective Groups in Organic Synthesis, second edition, John Wiley and Sons, New York, N.Y. (1991). The resulting amine can then be acylated with a sulfonyl chloride in an inert solvent, such as methylene chloride, preferably in the presence of an organic base such as pyridine, triethylamine, and the like. Removal of protective groups R5 and R6 can be accomplished using the methods described in Greene, T. W. and Wuts, P. G. M., Protective Groups in Organic Synthesis, second edition, John Wiley and Sons, New York, N.Y. (1991) to provide the final compound.
The following examples are illustrative, but not limiting, of the method and compositions of the present invention. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered and obvious to those skilled in the art are within the spirit and scope of the invention.